Project Cost is a field that represents if project costs are on budget or not
The cost field is currently not calculated in any way, but is included so you can manually set a cost level on a project.
This setting allows you to edit or create new Cost levels that can be set on a project.
The image below shows the default costs: Under, On and Over (Under budget, On budget and Over budget):
You can add new costs or edit the ones in the table. Clicking on the palette icon shows a color picker dialog.
The red "X" deletes the row.